Ejector and method of operating the same



Oct. 22, 1-929. DELAS EJECTOR AND METHOD OF OPERATING THE SAME Filed Sept. 8, 1926 IIIIIIIIIV// INVENTQR ALBERT DE LA5 ATTORNEY Patented Oct. 22, 1929 UNITED STATES PATENT OFFICE ALBERT DELAS, OF PARIS, FRANCE Application filed September 8, 1926, Serial No. 134,146, and in France October 26, 1925.

It is known that the stabilit of steam ejectors can be increased by coo ing off the part in which the compression of the motive fluid and of the entrained fluid takes place,

i. e. the difiuser, by any appropriate process, and especially by means of a current of water. This arrangement avoids the formation of the steam eddies which are one of the causes of the instability of ejectors.

It is known also that generally the thermic exchange between a wall and a fluid may be improved by high speed of the latter at contact with the wall. In the case considered above, this leads to a rapid circulation of the cooling water at the contact region of the diifuser, where eddies are more easily produced. However, the thermic exchange thus realized is very rapidly limited by the area of the diffuser walls, which is necessarily small.

Finally, and more especially in multi-stage compression ejectors, it has been suggested to condense the motive steam at the outlet of the diifuser in order either to avoid feature compression of this steam or simply to utilize the heat that it contains.

However, the construction of apparatus embodying all the various arrangements above described, has led so far to a compli- 39 cated and costly construction requiring many joints and special arrangements such as presse-toupes or diaphragms, which are necessary to remedy the bad effects of expansion.

The object of the present invention is a new arrangement for steam ejectors with cooled diffusers and arranged for condensation of the motive steam after compression, in which the lower part of the diffuser is .1 extended by an envelope of water circulating at great speed and acting as a cooled wall with intense thermic exchange. Also, the

diffuser itself is fixed only at one of its ends, in order to be able to expand freely, thus avoiding the use of any slip or deformable joints. Altogether, the construction of the whole of the apparatus is considerably simplified, notably on account of the reduction of the number of joints.

The single figure in partial section of the accompanying drawing illustrates my invention as applied to the first compression stage of an ejector with intermediate condenser.

The live steam is brought in at 1 into the ejector and expands when flowing out of the nozzle 2, while the aspired air or fluid arrives through the inlet 3 and is then entrained and compressed by the motive steam into the diffuser i, which is fixed only at its upper part at 5, by any appro riate means. This diffuser opens into cham er 6, where the motive steam is compressed.

The fluid to be extracte'd thus separated from the steam, is aspired through the passage 7 to the second stage of the ejector, which is not represented on the drawing, and which completes the compression.

At the same time the water to assure the stabilization-of the ejector and to condense the steam, flows in through the inlet 8 and spreads in the chamber 9, which it fills, and then flows at great speed through the circular opening 10 provided between the wall 11 and the diffuser 4. It flows in this way along the lower part of the diffuser, and

when it reaches the end of the diffuser at 12, it continues its course, forming a cylindrical envelope 13, which prolongs the diffuser and at the same time envelopes the steam jet.

- ,Thewhole of the diffuser is therefore constituted by the member 4 cooled by an envelopeof' water 13 which constitutes a cold wall having a particularly powerful action,

Tnon, which assures a sufiicient division to produce a good condensation.

Finally, after having been used the water is cleared out through the inlet 14 by any suitable process, such as pumping, or the equivalent.

The flow of water through inlet 8 and the starting of its flow through the opening 10 are effected by the vacuum existing in the intermediate condenser. The area of opening 10 must, in consequence, of this vacuum, be calculated to provide for copious flow of water as well as complete filling of the chamber 6.

The diffuser, being fixed only by its upper part at 5, can expand freely without the use of any slip joint or diaphragm and thereby the number of joints and of distinct parts in the apparatus is reduced to a minimum.

The present arrangement can be applied to any double or multistage steam ejector. It can be also applied-to the last stage compressing at atmospheric pressure, and if this is the case, the cooling and condensing water must then have a certain pressure to permit the flow described above.

A stage of compression can also be used provided with a device according to the present invention, in series with any other compression apparatus such as a pump, liquid or air or gas ejector, ventilator, etc.

Finally, the steam used can be other than water steam, the gas fluid to be extracted can be of any nature, and so can be the cooling and condensing liquid.

Having described my invention in such manner that it may be practiced by those skilled in the art and its benefits obtained I declare that what I claim is:

1. In an ejector the combination with a diffuser, of means for producing beyond the end of said diffuser a cooling fluid envelope forming in effect a continuation of the diffuser, said fluid envelope being unsupported by any surrounding walls of the ejector.

2. In an ejector the combination with a diffuser, of means for supplying cooling fluid about said diffuser, and means for producing beyond the end of said diffuser a cooling fluid envelope forming in effect a continuation of the diffuser, said fluid envelope being unsupported by any surounding walls of the ejector. I

3. In an ejector, the combination of a diffuser, a chamber surrounding said diffuser and adapted to be supplied with cooling fluid, said chamber being provided with an opening about said diffuser to produce an unsupported envelope of cooling fluid forming in effect a continuation of said diffuser, and a second chamber surrounding the end of said diffuser, said chamber being of sufficient size to permit the resolution of said fluid into drops without contacting with the walls of the second chamber,

4. A method of operating an ejector having a diffuser opening into a large chamber relatively to the diffuser, which comprises projecting a stream of cooling fluid along and past said diffuser into said chamber, to produce an elastic and unsupported envelope of cooling fluid forming in effect a continuation of said difluser.

5. A method of operating an ejector having a diffuser opening into a large chamber relatively to the diffuser which comprises circulating a stream of cooling fluid around said diffuser, then projecting said fluid along and past the end of said diffuser to produce an elastic and unsupported envelope of cooling fluid forming in effect a continuation of said diffuser.

6. In an ejector, the combination with a:

diffuser of means for producing beyond the end of said diffuser a cooling fluid envelope forming in effect an unconfined and elastic continuation of the diffuser.

7. In an ejector, a casing having an inlet' for motive fluid and an inlet for fluid to be ejected, a second casing having an apertured partition dividing the same into separate chambers which chambers are relatively larger than and spaced from the diffuser, a diffuser supported at its inlet end by the first casing and passing freely through the up ier chamber and partition and extending eyond the partition into the lower chamber, said second casing having an inlet for cooling fluid intothe upper chamber-{said diffuser and partition being so constructed as to permit an envelope of cooling fluid to flow over the surface of the lower end of the diffuser unsupported except for its contact with the diffuser to the discharge end of said diffuser which cooling fluid is projected beyond said discharge end to form in effect an elastic unsupported continuation of the diffuser. V I

In testimony whereof, I have hereunto affixed my signature this 23rd day of June, 1926.

ALBERT DELAS. 

